Asterix
I'm not a plumber but I am handy in matters like these. I would not want you to spend money not needed either. But there does come times when it is unavoidable. This may be that time....
Lets try the basics first.
Be sure there is electrical power supplied to the disposal. If the unit has it's own power cord, it's plugged into a wall outlet. Be sure the wall switch and outlet have power. Plug a lamp into the outlet and test.
If power is present, there may be an internal fuse in the disposal. Or the internal rest button may be defective. Worse case is the motor is burned out. Determining the actual cause takes a step by step diagnostic process.
That model may or may not have a center break away coupling. That slight effort to turn the cutter blades may indicate binding. Which may be caused by a wornout motor. The internal motor magnets will hold the armature too securely to allow the it to turn freely.
Most likely someone else has other possible causes and ways to test and or fix the machine. I can only offer you generic and or basic possibilities. Be a good suggestion to check back on your question several more times. Likely to get more help from others...
Helping You Too.
Good Luck.
ApplianceTech2
Natural & Propane Gas Appliance Service Rep.
Use Logic and Common Sense When All Else Fails